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/* packet-bananna.c
* Routines for the Twisted Banana serialization protocol dissection
* Copyright 2009, Gerald Combs <gerald@wireshark.org>
*
* Wireshark - Network traffic analyzer
* By Gerald Combs <gerald@wireshark.org>
* Copyright 1998 Gerald Combs
*
* SPDX-License-Identifier: GPL-2.0-or-later
*/
/*
* Based on "Banana Protocol Specifications"
* https://twisted.org/documents/16.1.1/core/specifications/banana.html
*/
#include "config.h"
#include <epan/packet.h>
#include <epan/expert.h>
void proto_register_banana(void);
void proto_reg_handoff_banana(void);
/* Initialize the protocol and registered fields */
static int proto_banana;
static int hf_banana_list;
static int hf_banana_int;
static int hf_banana_string;
static int hf_banana_neg_int;
static int hf_banana_float;
static int hf_banana_lg_int;
static int hf_banana_lg_neg_int;
static int hf_banana_pb;
/* Initialize the subtree pointers */
static int ett_banana;
static int ett_list;
static expert_field ei_banana_unknown_type;
static expert_field ei_banana_too_many_value_bytes;
static expert_field ei_banana_length_too_long;
static expert_field ei_banana_value_too_large;
static expert_field ei_banana_pb_error;
static dissector_handle_t banana_handle;
#define BE_LIST 0x80
#define BE_INT 0x81
#define BE_STRING 0x82
#define BE_NEG_INT 0x83
#define BE_FLOAT 0x84
#define BE_LG_INT 0x85
#define BE_LG_NEG_INT 0x86
#define BE_PB 0x87
#define is_element(b) (b >= BE_LIST && b <= BE_PB)
static const value_string type_vals[] = {
{ BE_LIST, "List" },
{ BE_INT, "Integer" },
{ BE_STRING, "String" },
{ BE_NEG_INT, "Negative Integer" },
{ BE_FLOAT, "Float" },
{ BE_LG_INT, "Large Integer" },
{ BE_LG_NEG_INT, "Large Negative Integer" },
{ BE_PB, "pb Profile"},
{ 0, NULL }
};
static const value_string pb_vals[] = {
{ 0x01, "None" },
{ 0x02, "class" },
{ 0x03, "dereference" },
{ 0x04, "reference" },
{ 0x05, "dictionary" },
{ 0x06, "function" },
{ 0x07, "instance" },
{ 0x08, "list" },
{ 0x09, "module" },
{ 0x0a, "persistent" },
{ 0x0b, "tuple" },
{ 0x0c, "unpersistable" },
{ 0x0d, "copy" },
{ 0x0e, "cache" },
{ 0x0f, "cached" },
{ 0x10, "remote" },
{ 0x11, "local" },
{ 0x12, "lcache" },
{ 0x13, "version" },
{ 0x14, "login" },
{ 0x15, "password" },
{ 0x16, "challenge" },
{ 0x17, "logged_in" },
{ 0x18, "not_logged_in" },
{ 0x19, "cachemessage" },
{ 0x1a, "message" },
{ 0x1b, "answer" },
{ 0x1c, "error" },
{ 0x1d, "decref" },
{ 0x1e, "decache" },
{ 0x1f, "uncache" },
{ 0, NULL }
};
#define MAX_ELEMENT_VAL 2147483647 /* Max TE value */
#define MAX_ELEMENT_INT_LEN 4
#define MAX_ELEMENT_VAL_LEN 8
/* Dissect the packets */
static int
// NOLINTNEXTLINE(misc-no-recursion)
dissect_banana_element(tvbuff_t *tvb, packet_info *pinfo, proto_tree *tree, int offset) {
proto_item *ti;
proto_tree *list_tree;
uint8_t byte = 0;
int64_t val = 0;
int val_len = 0;
int start_offset = offset;
int old_offset;
int i;
/* Accumulate our value/length 'til we hit a valid type */
while (tvb_reported_length_remaining(tvb, offset) > 0) {
byte = tvb_get_uint8(tvb, offset);
offset++;
if (byte & 0x80) {
if (is_element(byte)) {
break;
} else {
expert_add_info_format(pinfo, NULL, &ei_banana_unknown_type, "Unknown type %u", byte);
}
} else {
val_len++;
if (val_len > MAX_ELEMENT_VAL_LEN) {
expert_add_info(pinfo, NULL, &ei_banana_too_many_value_bytes);
}
val += byte + (val << 7);
}
}
/* Type */
switch (byte) {
case BE_LIST:
if (val > MAX_ELEMENT_VAL) {
expert_add_info_format(pinfo, NULL, &ei_banana_length_too_long, "List length %" PRId64 " longer than we can handle", val);
}
ti = proto_tree_add_uint_format_value(tree, hf_banana_list, tvb, start_offset, offset - start_offset - 1, (uint32_t) val, "(%d items)", (int) val);
list_tree = proto_item_add_subtree(ti, ett_list);
for (i = 0; i < val; i++) {
old_offset = offset;
increment_dissection_depth(pinfo);
offset += dissect_banana_element(tvb, pinfo, list_tree, offset);
decrement_dissection_depth(pinfo);
if (offset <= old_offset) {
return offset - start_offset;
}
}
break;
case BE_INT:
if (val > MAX_ELEMENT_VAL) {
expert_add_info_format(pinfo, NULL, &ei_banana_value_too_large, "Integer value %" PRId64 " too large", val);
}
proto_tree_add_uint(tree, hf_banana_int, tvb, start_offset, offset - start_offset, (uint32_t) val);
break;
case BE_STRING:
if (val > MAX_ELEMENT_VAL) {
expert_add_info_format(pinfo, NULL, &ei_banana_length_too_long, "String length %" PRId64 " longer than we can handle", val);
}
proto_tree_add_item(tree, hf_banana_string, tvb, offset, (uint32_t) val, ENC_ASCII);
offset += (int) val;
break;
case BE_NEG_INT:
if (val > MAX_ELEMENT_VAL) {
expert_add_info_format(pinfo, NULL, &ei_banana_value_too_large, "Integer value -%" PRId64 " too large", val);
}
proto_tree_add_int(tree, hf_banana_neg_int, tvb, start_offset, offset - start_offset, (int32_t) val * -1);
break;
case BE_FLOAT:
proto_tree_add_item(tree, hf_banana_float, tvb, offset, 8, ENC_BIG_ENDIAN);
offset += 8;
break;
case BE_LG_INT:
proto_tree_add_item(tree, hf_banana_lg_int, tvb, start_offset, offset - start_offset, ENC_NA);
break;
case BE_LG_NEG_INT:
proto_tree_add_item(tree, hf_banana_lg_neg_int, tvb, start_offset, offset - start_offset, ENC_NA);
break;
case BE_PB:
if (val_len > 1) {
expert_add_info(pinfo, NULL, &ei_banana_pb_error);
}
/*
* The spec says the pb dictionary value comes after the tag.
* In real-world captures it comes before.
*/
proto_tree_add_item(tree, hf_banana_pb, tvb, offset - 2, 1, ENC_BIG_ENDIAN);
break;
default:
return 0;
}
return offset - start_offset;
}
static int
dissect_banana(tvbuff_t *tvb, packet_info *pinfo, proto_tree *tree, void *data _U_) {
uint8_t byte = 0;
int offset = 0, old_offset;
proto_item *ti;
proto_tree *banana_tree;
/* Check that there's enough data */
if (tvb_reported_length(tvb) < 2)
return 0;
/* Fill in our protocol and info columns */
col_set_str(pinfo->cinfo, COL_PROTOCOL, "Banana");
while (tvb_reported_length_remaining(tvb, offset) > 0 && offset < MAX_ELEMENT_VAL_LEN) {
byte = tvb_get_uint8(tvb, offset);
if (is_element(byte))
break;
offset++;
}
col_add_fstr(pinfo->cinfo, COL_INFO, "First element: %s",
val_to_str(byte, type_vals, "Unknown type: %u"));
/* Create display subtree for the protocol */
ti = proto_tree_add_item(tree, proto_banana, tvb, 0, -1, ENC_NA);
banana_tree = proto_item_add_subtree(ti, ett_banana);
offset = 0;
old_offset = -1;
while (offset > old_offset) {
old_offset = offset;
offset += dissect_banana_element(tvb, pinfo, banana_tree, offset);
}
/* Return the amount of data this dissector was able to dissect */
return tvb_reported_length(tvb);
}
/* Register the protocol with Wireshark */
void
proto_register_banana(void)
{
static hf_register_info hf[] = {
{ &hf_banana_list,
{ "List Length", "banana.list",
FT_UINT32, BASE_DEC, NULL, 0,
"Banana list", HFILL }
},
{ &hf_banana_int,
{ "Integer", "banana.int",
FT_UINT32, BASE_DEC, NULL, 0,
"Banana integer", HFILL }
},
{ &hf_banana_string,
{ "String", "banana.string",
FT_STRING, BASE_NONE, NULL, 0,
"Banana string", HFILL }
},
{ &hf_banana_neg_int,
{ "Negative Integer", "banana.neg_int",
FT_INT32, BASE_DEC, NULL, 0,
"Banana negative integer", HFILL }
},
{ &hf_banana_float,
{ "Float", "banana.float",
FT_DOUBLE, BASE_NONE, NULL, 0,
"Banana float", HFILL }
},
{ &hf_banana_lg_int,
{ "Float", "banana.lg_int",
FT_BYTES, BASE_NONE, NULL, 0,
"Banana large integer", HFILL }
},
{ &hf_banana_lg_neg_int,
{ "Float", "banana.lg_neg_int",
FT_BYTES, BASE_NONE, NULL, 0,
"Banana large negative integer", HFILL }
},
{ &hf_banana_pb,
{ "pb Profile Value", "banana.pb",
FT_UINT8, BASE_HEX, VALS(pb_vals), 0,
"Banana Perspective Broker Profile Value", HFILL }
}
};
expert_module_t* expert_banana;
/* Setup protocol subtree array */
static int *ett[] = {
&ett_banana,
&ett_list
};
static ei_register_info ei[] = {
{ &ei_banana_unknown_type, { "banana.unknown_type", PI_UNDECODED, PI_ERROR, "Unknown type", EXPFILL }},
{ &ei_banana_too_many_value_bytes, { "banana.too_many_value_bytes", PI_UNDECODED, PI_ERROR, "Too many value/length bytes", EXPFILL }},
{ &ei_banana_length_too_long, { "banana.length_too_long", PI_UNDECODED, PI_ERROR, "Length too long", EXPFILL }},
{ &ei_banana_value_too_large, { "banana.value_too_large", PI_MALFORMED, PI_ERROR, "Value too large", EXPFILL }},
{ &ei_banana_pb_error, { "banana.pb_error", PI_MALFORMED, PI_ERROR, "More than 1 byte before pb", EXPFILL }},
};
/* Register the protocol name and description */
proto_banana = proto_register_protocol("Twisted Banana", "Banana", "banana");
/* Required function calls to register the header fields and subtrees used */
proto_register_field_array(proto_banana, hf, array_length(hf));
proto_register_subtree_array(ett, array_length(ett));
expert_banana = expert_register_protocol(proto_banana);
expert_register_field_array(expert_banana, ei, array_length(ei));
banana_handle = register_dissector("banana", dissect_banana, proto_banana);
}
void
proto_reg_handoff_banana(void)
{
dissector_add_uint_range_with_preference("tcp.port", "", banana_handle);
}
/*
* Editor modelines - https://www.wireshark.org/tools/modelines.html
*
* Local variables:
* c-basic-offset: 4
* tab-width: 8
* indent-tabs-mode: nil
* End:
*
* ex: set shiftwidth=4 tabstop=8 expandtab:
* :indentSize=4:tabSize=8:noTabs=true:
*/
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